Conventionally, there is an inkjet type printer, which prints an image or the like by injecting ink droplets on paper, as a liquid injection apparatus that injects a liquid to a target. Some inkjet type printers have a plurality of ink-retained cartridges (liquid containers) mounted on a carriage and a memory element provided on each cartridge to manage the remaining amount of the ink. Information about the color and remaining amount of the ink in the associated cartridge is stored in each memory element. Before printing takes place, the remaining amount of the ink in each cartridge is acquired from the memory element and is displayed on a monitor. Based on the displayed remaining amount of the ink, a user determines whether or not there is a possibility that the ink will run out during printing. In the case where there is a possibility that the ink will run out during printing, the user replaces the associated cartridge with a cartridge having a larger amount of ink remaining.
That is, a user first presses a replacement button provided on the printer to move the carriage at a standby position to a replacement position. Then, the user specifies a cartridge to be replaced from among cartridges mounted on the carriage based on the display on the monitor and replaces this cartridge with another one. Thereafter, as the user presses the replacement button again, the carriage returns to the standby position from the replacement position.
With the above-described printer, a user should determine whether or not a cartridge should be replaced based on the remaining amount of ink displayed on the monitor. At the time of replacing a cartridge, the user needs to press the replacement button to move the carriage from the standby position to the replacement position. Further, if the user removes a cartridge from the carriage for replacement while the printer is writing information on the remaining amount of ink or the like in the memory element of the cartridge, the information is not written in the memory element accurately. Therefore, the user should perform a cartridge replacement task while paying attention to a process executed by the printer.
As described above, conventionally, a heavy burden is put on a user in a cartridge replacement task and the replacement task is troublesome.